The present invention relates generally to cylinder locks, and more particularly to cylinder locks that use a complementary configured key and sidebar in conjunction with conventional lock mechanisms, such as tumblers. The sidebar is positioned at a precise axial position by a key positioning mechanism on the key, wherein the sidebar can engage grooves on the side of the key blade. This positioning facilitates the shifting of the sidebar from a locked position to an unlocked position and the key can rotate the cylinder plug.
Cylinder locks for locking doors and other similar structures are well known in the art. Typically these cylinder locks include a cylinder shell, cylinder plug located within the cylinder shell and tumblers extending there through. Further, a locking member, such as a deadbolt, rotates with the cylinder plug to lock or unlock the door, cabinet or other structure.
WO93/09317 (Prunbauer) describes a lock and a key system that utilizes a sidebar mechanism to prevent a cylinder from rotating, but is silent on the axial movement of the sidebar. Further, U.S. Pat. No. 5,797,287 (Prunbauer) is directed to a key, but discloses a system similar to Prunbauer WO093/09317.
German Patent DE2828343, issued to Perkut, discloses yet another key and lock system that uses tumblers to match up with the key ridges and further discloses a ball to use with the sidebar to facilitate rotation. U.S. Pat. No. 5,615,566, issued to Brandt, discloses a lock that has an axially sliding member at the back of the plug, as a secondary locking mechanism, used in conjunction with conventional tumblers.
Further, U.S. Pat. Nos. 6,477,875 and 6,945,082, both issued to Field et al., disclose a lock system that combines an axially sliding member operated by a contact tab integrally formed on a key, to facilitate release of the separate sidebar.
Notwithstanding the prior art, there still remains a need for a lock and key system that, among other things, combines the functions of an axially sliding member and a sidebar. Benefits of such a system include minimizing of moving parts, preferably making lock breakdown less likely, and increasing security of the lock itself.